Results 81 to 90 of about 128,769 (349)
Fossil biomass preserved as graphitic carbon in a late paleoproterozoic banded iron formation metamorphosed at more than 550°C [PDF]
, 2019 Metamorphism is thought to destroy microfossils, partly through devolatilization and graphitization of biogenic organic matter. However, the extent to which there is a loss of molecular, elemental and isotope signatures from biomass during high ...
De Gregorio, BT +9 more
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Raman Study of the Slobodka Ordinary Chondrite
Journal of Raman Spectroscopy, EarlyView.The texture and mineral chemistry of Slobodka are most consistent with L4 chondrites, exhibiting strong shock metamorphism characteristic of shock stage S4, including irregular and planar fractures, undulatory extinction, and mosaicism in olivine, pyroxene, and plagioclase.
M. Simopoulou +10 more
wiley +1 more source
Accretionary Tectonics of the North American Cordillera [PDF]
, 1983 Continental geology stands on the threshold of a change that is likely to be as fundamental as plate-tectonic theory was for marine geology. Ongoing seismic-reflection investigations into the deep crustal structure of North America are verifying that ...
Saleeby, Jason B.
core +2 more sources
Frontiers in Earth ScienceIntroductionThe east-west trending Khondalite Belt, located on the northern margin of the North China Craton, is linked to the Paleoproterozoic Columbia supercontinent’s evolution.
Hao Hu +6 more
doaj +1 more source
Journal of Raman Spectroscopy, EarlyView.Palynofacies assemblages from the onshore Potiguar Basin display a wide thermal maturity range, with vitrinite reflectance (%Ro) values of 0.46–2.72 measured from nine samples at depths of 1059–4443 m. A strong correlation exists between %Ro and Raman parameters, specifically the G‐band's full width at half maximum.
Gabriel A. Barberes +14 more
wiley +1 more source
Zircon dissolution in a ductile shear zone, Monte Rosa granite gneiss, northern Italy [PDF]
, 2008 The sizes, distributions and shapes of zircon grains within variably deformed granite gneiss from the western Alps have been studied. Zircon shows numerous indicators of a metamorphic response in both the host gneiss and a 5 cm wide continuous ductile ...
Dal Piaz +14 more
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Metamorphic Inheritance, Lower‐Crustal Earthquakes, and Continental Rifting
Geochemistry, Geophysics, GeosystemsThe Malawi Rift is localized within Precambrian amphibolite‐granulite facies metamorphic belts, bounded by up to 150 km long border faults, and generates earthquakes throughout ∼40 km thick crust.
Å. Fagereng +3 more
doaj +1 more source
Electron Microprobe Reintegration Method for Clinopyroxene Breakdown with Lamellae Exsolution
Yankuang ceshiPyroxene is an important rock-forming mineral in magmatic to metamorphic rocks, which often possesses certain breakdown texture with lamellae exsolution under temperature and pressure changes.
Xiaoli LI, Lifei ZHANG
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Journal of Raman Spectroscopy, EarlyView.This paper presents a new protocol for the laboratory preparation of archaeological samples. Ceramics that have been hand‐crafted using different sediments as raw materials were collected in a Roman Villa sited in Fiumana (FC), Italy. This method aims at concentrating and analysing heavy minerals in the 15–250 μm grain size fraction, studying the ...
S. Andò +6 more
wiley +1 more source
Shoshonitic enclaves in the high Sr/Y Nyemo pluton, southern Tibet: Implications for Oligocene magma mixing and the onset of extension of the southern Lhasa terrane [PDF]
, 2020 Post-collisional potassic and high Sr/Y magmatism in the Lhasa terrane provides critical constraints on the timing and mechanism of subduction of Indian lithosphere and its role in the uplift of the Tibetan Plateau.
Asimow, Paul D. +8 more
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